Java tutorial
//package com.java2s; import java.util.Map; public class Main { /** * Sums up all the associated values from the specified * <code>map</code> * @param map * @return */ public static <K> double sum(Map<K, ? extends Number> map) { double sum = 0.0; for (Number value : map.values()) { sum += value.doubleValue(); } return sum; } }